open-nomad/vendor/github.com/StackExchange/wmi/wmi.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

487 lines
13 KiB
Go

// +build windows
/*
Package wmi provides a WQL interface for WMI on Windows.
Example code to print names of running processes:
type Win32_Process struct {
Name string
}
func main() {
var dst []Win32_Process
q := wmi.CreateQuery(&dst, "")
err := wmi.Query(q, &dst)
if err != nil {
log.Fatal(err)
}
for i, v := range dst {
println(i, v.Name)
}
}
*/
package wmi
import (
"bytes"
"errors"
"fmt"
"log"
"os"
"reflect"
"runtime"
"strconv"
"strings"
"sync"
"time"
"github.com/go-ole/go-ole"
"github.com/go-ole/go-ole/oleutil"
)
var l = log.New(os.Stdout, "", log.LstdFlags)
var (
ErrInvalidEntityType = errors.New("wmi: invalid entity type")
// ErrNilCreateObject is the error returned if CreateObject returns nil even
// if the error was nil.
ErrNilCreateObject = errors.New("wmi: create object returned nil")
lock sync.Mutex
)
// S_FALSE is returned by CoInitializeEx if it was already called on this thread.
const S_FALSE = 0x00000001
// QueryNamespace invokes Query with the given namespace on the local machine.
func QueryNamespace(query string, dst interface{}, namespace string) error {
return Query(query, dst, nil, namespace)
}
// Query runs the WQL query and appends the values to dst.
//
// dst must have type *[]S or *[]*S, for some struct type S. Fields selected in
// the query must have the same name in dst. Supported types are all signed and
// unsigned integers, time.Time, string, bool, or a pointer to one of those.
// Array types are not supported.
//
// By default, the local machine and default namespace are used. These can be
// changed using connectServerArgs. See
// http://msdn.microsoft.com/en-us/library/aa393720.aspx for details.
//
// Query is a wrapper around DefaultClient.Query.
func Query(query string, dst interface{}, connectServerArgs ...interface{}) error {
if DefaultClient.SWbemServicesClient == nil {
return DefaultClient.Query(query, dst, connectServerArgs...)
}
return DefaultClient.SWbemServicesClient.Query(query, dst, connectServerArgs...)
}
// A Client is an WMI query client.
//
// Its zero value (DefaultClient) is a usable client.
type Client struct {
// NonePtrZero specifies if nil values for fields which aren't pointers
// should be returned as the field types zero value.
//
// Setting this to true allows stucts without pointer fields to be used
// without the risk failure should a nil value returned from WMI.
NonePtrZero bool
// PtrNil specifies if nil values for pointer fields should be returned
// as nil.
//
// Setting this to true will set pointer fields to nil where WMI
// returned nil, otherwise the types zero value will be returned.
PtrNil bool
// AllowMissingFields specifies that struct fields not present in the
// query result should not result in an error.
//
// Setting this to true allows custom queries to be used with full
// struct definitions instead of having to define multiple structs.
AllowMissingFields bool
// SWbemServiceClient is an optional SWbemServices object that can be
// initialized and then reused across multiple queries. If it is null
// then the method will initialize a new temporary client each time.
SWbemServicesClient *SWbemServices
}
// DefaultClient is the default Client and is used by Query, QueryNamespace
var DefaultClient = &Client{}
// Query runs the WQL query and appends the values to dst.
//
// dst must have type *[]S or *[]*S, for some struct type S. Fields selected in
// the query must have the same name in dst. Supported types are all signed and
// unsigned integers, time.Time, string, bool, or a pointer to one of those.
// Array types are not supported.
//
// By default, the local machine and default namespace are used. These can be
// changed using connectServerArgs. See
// http://msdn.microsoft.com/en-us/library/aa393720.aspx for details.
func (c *Client) Query(query string, dst interface{}, connectServerArgs ...interface{}) error {
dv := reflect.ValueOf(dst)
if dv.Kind() != reflect.Ptr || dv.IsNil() {
return ErrInvalidEntityType
}
dv = dv.Elem()
mat, elemType := checkMultiArg(dv)
if mat == multiArgTypeInvalid {
return ErrInvalidEntityType
}
lock.Lock()
defer lock.Unlock()
runtime.LockOSThread()
defer runtime.UnlockOSThread()
err := ole.CoInitializeEx(0, ole.COINIT_MULTITHREADED)
if err != nil {
oleCode := err.(*ole.OleError).Code()
if oleCode != ole.S_OK && oleCode != S_FALSE {
return err
}
}
defer ole.CoUninitialize()
unknown, err := oleutil.CreateObject("WbemScripting.SWbemLocator")
if err != nil {
return err
} else if unknown == nil {
return ErrNilCreateObject
}
defer unknown.Release()
wmi, err := unknown.QueryInterface(ole.IID_IDispatch)
if err != nil {
return err
}
defer wmi.Release()
// service is a SWbemServices
serviceRaw, err := oleutil.CallMethod(wmi, "ConnectServer", connectServerArgs...)
if err != nil {
return err
}
service := serviceRaw.ToIDispatch()
defer serviceRaw.Clear()
// result is a SWBemObjectSet
resultRaw, err := oleutil.CallMethod(service, "ExecQuery", query)
if err != nil {
return err
}
result := resultRaw.ToIDispatch()
defer resultRaw.Clear()
count, err := oleInt64(result, "Count")
if err != nil {
return err
}
enumProperty, err := result.GetProperty("_NewEnum")
if err != nil {
return err
}
defer enumProperty.Clear()
enum, err := enumProperty.ToIUnknown().IEnumVARIANT(ole.IID_IEnumVariant)
if err != nil {
return err
}
if enum == nil {
return fmt.Errorf("can't get IEnumVARIANT, enum is nil")
}
defer enum.Release()
// Initialize a slice with Count capacity
dv.Set(reflect.MakeSlice(dv.Type(), 0, int(count)))
var errFieldMismatch error
for itemRaw, length, err := enum.Next(1); length > 0; itemRaw, length, err = enum.Next(1) {
if err != nil {
return err
}
err := func() error {
// item is a SWbemObject, but really a Win32_Process
item := itemRaw.ToIDispatch()
defer item.Release()
ev := reflect.New(elemType)
if err = c.loadEntity(ev.Interface(), item); err != nil {
if _, ok := err.(*ErrFieldMismatch); ok {
// We continue loading entities even in the face of field mismatch errors.
// If we encounter any other error, that other error is returned. Otherwise,
// an ErrFieldMismatch is returned.
errFieldMismatch = err
} else {
return err
}
}
if mat != multiArgTypeStructPtr {
ev = ev.Elem()
}
dv.Set(reflect.Append(dv, ev))
return nil
}()
if err != nil {
return err
}
}
return errFieldMismatch
}
// ErrFieldMismatch is returned when a field is to be loaded into a different
// type than the one it was stored from, or when a field is missing or
// unexported in the destination struct.
// StructType is the type of the struct pointed to by the destination argument.
type ErrFieldMismatch struct {
StructType reflect.Type
FieldName string
Reason string
}
func (e *ErrFieldMismatch) Error() string {
return fmt.Sprintf("wmi: cannot load field %q into a %q: %s",
e.FieldName, e.StructType, e.Reason)
}
var timeType = reflect.TypeOf(time.Time{})
// loadEntity loads a SWbemObject into a struct pointer.
func (c *Client) loadEntity(dst interface{}, src *ole.IDispatch) (errFieldMismatch error) {
v := reflect.ValueOf(dst).Elem()
for i := 0; i < v.NumField(); i++ {
f := v.Field(i)
of := f
isPtr := f.Kind() == reflect.Ptr
if isPtr {
ptr := reflect.New(f.Type().Elem())
f.Set(ptr)
f = f.Elem()
}
n := v.Type().Field(i).Name
if !f.CanSet() {
return &ErrFieldMismatch{
StructType: of.Type(),
FieldName: n,
Reason: "CanSet() is false",
}
}
prop, err := oleutil.GetProperty(src, n)
if err != nil {
if !c.AllowMissingFields {
errFieldMismatch = &ErrFieldMismatch{
StructType: of.Type(),
FieldName: n,
Reason: "no such struct field",
}
}
continue
}
defer prop.Clear()
switch val := prop.Value().(type) {
case int8, int16, int32, int64, int:
v := reflect.ValueOf(val).Int()
switch f.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
f.SetInt(v)
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
f.SetUint(uint64(v))
default:
return &ErrFieldMismatch{
StructType: of.Type(),
FieldName: n,
Reason: "not an integer class",
}
}
case uint8, uint16, uint32, uint64:
v := reflect.ValueOf(val).Uint()
switch f.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
f.SetInt(int64(v))
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
f.SetUint(v)
default:
return &ErrFieldMismatch{
StructType: of.Type(),
FieldName: n,
Reason: "not an integer class",
}
}
case string:
switch f.Kind() {
case reflect.String:
f.SetString(val)
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
iv, err := strconv.ParseInt(val, 10, 64)
if err != nil {
return err
}
f.SetInt(iv)
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
uv, err := strconv.ParseUint(val, 10, 64)
if err != nil {
return err
}
f.SetUint(uv)
case reflect.Struct:
switch f.Type() {
case timeType:
if len(val) == 25 {
mins, err := strconv.Atoi(val[22:])
if err != nil {
return err
}
val = val[:22] + fmt.Sprintf("%02d%02d", mins/60, mins%60)
}
t, err := time.Parse("20060102150405.000000-0700", val)
if err != nil {
return err
}
f.Set(reflect.ValueOf(t))
}
}
case bool:
switch f.Kind() {
case reflect.Bool:
f.SetBool(val)
default:
return &ErrFieldMismatch{
StructType: of.Type(),
FieldName: n,
Reason: "not a bool",
}
}
case float32:
switch f.Kind() {
case reflect.Float32:
f.SetFloat(float64(val))
default:
return &ErrFieldMismatch{
StructType: of.Type(),
FieldName: n,
Reason: "not a Float32",
}
}
default:
if f.Kind() == reflect.Slice {
switch f.Type().Elem().Kind() {
case reflect.String:
safeArray := prop.ToArray()
if safeArray != nil {
arr := safeArray.ToValueArray()
fArr := reflect.MakeSlice(f.Type(), len(arr), len(arr))
for i, v := range arr {
s := fArr.Index(i)
s.SetString(v.(string))
}
f.Set(fArr)
}
case reflect.Uint8:
safeArray := prop.ToArray()
if safeArray != nil {
arr := safeArray.ToValueArray()
fArr := reflect.MakeSlice(f.Type(), len(arr), len(arr))
for i, v := range arr {
s := fArr.Index(i)
s.SetUint(reflect.ValueOf(v).Uint())
}
f.Set(fArr)
}
default:
return &ErrFieldMismatch{
StructType: of.Type(),
FieldName: n,
Reason: fmt.Sprintf("unsupported slice type (%T)", val),
}
}
} else {
typeof := reflect.TypeOf(val)
if typeof == nil && (isPtr || c.NonePtrZero) {
if (isPtr && c.PtrNil) || (!isPtr && c.NonePtrZero) {
of.Set(reflect.Zero(of.Type()))
}
break
}
return &ErrFieldMismatch{
StructType: of.Type(),
FieldName: n,
Reason: fmt.Sprintf("unsupported type (%T)", val),
}
}
}
}
return errFieldMismatch
}
type multiArgType int
const (
multiArgTypeInvalid multiArgType = iota
multiArgTypeStruct
multiArgTypeStructPtr
)
// checkMultiArg checks that v has type []S, []*S for some struct type S.
//
// It returns what category the slice's elements are, and the reflect.Type
// that represents S.
func checkMultiArg(v reflect.Value) (m multiArgType, elemType reflect.Type) {
if v.Kind() != reflect.Slice {
return multiArgTypeInvalid, nil
}
elemType = v.Type().Elem()
switch elemType.Kind() {
case reflect.Struct:
return multiArgTypeStruct, elemType
case reflect.Ptr:
elemType = elemType.Elem()
if elemType.Kind() == reflect.Struct {
return multiArgTypeStructPtr, elemType
}
}
return multiArgTypeInvalid, nil
}
func oleInt64(item *ole.IDispatch, prop string) (int64, error) {
v, err := oleutil.GetProperty(item, prop)
if err != nil {
return 0, err
}
defer v.Clear()
i := int64(v.Val)
return i, nil
}
// CreateQuery returns a WQL query string that queries all columns of src. where
// is an optional string that is appended to the query, to be used with WHERE
// clauses. In such a case, the "WHERE" string should appear at the beginning.
func CreateQuery(src interface{}, where string) string {
var b bytes.Buffer
b.WriteString("SELECT ")
s := reflect.Indirect(reflect.ValueOf(src))
t := s.Type()
if s.Kind() == reflect.Slice {
t = t.Elem()
}
if t.Kind() != reflect.Struct {
return ""
}
var fields []string
for i := 0; i < t.NumField(); i++ {
fields = append(fields, t.Field(i).Name)
}
b.WriteString(strings.Join(fields, ", "))
b.WriteString(" FROM ")
b.WriteString(t.Name())
b.WriteString(" " + where)
return b.String()
}